1. FIELD OF THE INVENTION
This invention is in the general field of sound deadening materials used in building or other areas and is more particularly in the field of a sound deadening material which is also fire resistant and of low thermal conductivity. This invention is even more limited in being directed to a sound deadening material which has the further quality that is impervious to and unaffected by oil fumes within ships and the like.
2. DESCRIPTION OF THE PRIOR ART
There are great quantities of acoustical materials of various configuration and composition used in buildings and other confined areas. Such materials may be of loosely woven fibre, perforated elements, specially shaped elements, and the like. Each of such materials have certain characteristics; such as obsorption, transfer, passage, reflection, or the like, of sound waves coming in contact with the material.
Most of the materials used for this purpose are unsuited to many applications for a wide variety of reasons. In some instances the material is unsuited to conditions of cleanliness which may be desired (due to dusting and the like) or because of the necessity of complete protection against fire or moisture, or for a variety of other reasons. In certain circumstances, such as in the engine rooms of ships, and the like, there are oil fumes in the air, which frequently impregnate and contaminate the various sound deadening materials.
The present invention is a material which entraps sound waves and is non-dusting, is fire retardant, and is generally unaffected by chemicals. It is capable of economical formation in large segments and segments of irregular shapes. It is capable of formation, assembly, and repair in an economical manner in the field. By the ue of a special membrane, this invention is further distinguished from the prior art.